diff options
Diffstat (limited to 'src/ext')
| -rw-r--r-- | src/ext/ed25519/ref10/ed25519_ref10.h | 5 | ||||
| -rw-r--r-- | src/ext/ed25519/ref10/keyconv.c | 37 | ||||
| -rw-r--r-- | src/ext/include.am | 3 |
3 files changed, 44 insertions, 1 deletions
diff --git a/src/ext/ed25519/ref10/ed25519_ref10.h b/src/ext/ed25519/ref10/ed25519_ref10.h index cd0244f306..da8cea19f0 100644 --- a/src/ext/ed25519/ref10/ed25519_ref10.h +++ b/src/ext/ed25519/ref10/ed25519_ref10.h @@ -16,4 +16,9 @@ int ed25519_ref10_sign( const unsigned char *m,uint64_t mlen, const unsigned char *sk, const unsigned char *pk); +/* Added in Tor */ +int ed25519_ref10_pubkey_from_curve25519_pubkey(unsigned char *out, + const unsigned char *inp, + int signbit); + #endif diff --git a/src/ext/ed25519/ref10/keyconv.c b/src/ext/ed25519/ref10/keyconv.c new file mode 100644 index 0000000000..854b150d69 --- /dev/null +++ b/src/ext/ed25519/ref10/keyconv.c @@ -0,0 +1,37 @@ +/* Added to ref10 for Tor. We place this in the public domain. Alternatively, + * you may have it under the Creative Commons 0 "CC0" license. */ +#include "fe.h" +#include "ed25519_ref10.h" + +int ed25519_ref10_pubkey_from_curve25519_pubkey(unsigned char *out, + const unsigned char *inp, + int signbit) +{ + fe u; + fe one; + fe y; + fe uplus1; + fe uminus1; + fe inv_uplus1; + + /* From prop228: + + Given a curve25519 x-coordinate (u), we can get the y coordinate + of the ed25519 key using + + y = (u-1)/(u+1) + */ + fe_frombytes(u, inp); + fe_1(one); + fe_sub(uminus1, u, one); + fe_add(uplus1, u, one); + fe_invert(inv_uplus1, uplus1); + fe_mul(y, uminus1, inv_uplus1); + + fe_tobytes(out, y); + + /* propagate sign. */ + out[31] |= (!!signbit) << 7; + + return 0; +} diff --git a/src/ext/include.am b/src/ext/include.am index 69e7823583..45d7dc565a 100644 --- a/src/ext/include.am +++ b/src/ext/include.am @@ -56,7 +56,8 @@ src_ext_ed25519_ref10_libed25519_ref10_a_SOURCES= \ src/ext/ed25519/ref10/open.c \ src/ext/ed25519/ref10/sc_muladd.c \ src/ext/ed25519/ref10/sc_reduce.c \ - src/ext/ed25519/ref10/sign.c + src/ext/ed25519/ref10/sign.c \ + src/ext/ed25519/ref10/keyconv.c ED25519_REF10_HDRS = \ src/ext/ed25519/ref10/api.h \ |